1. Field of Invention
This invention relates generally to intermodal transport systems and, more particularly, to an improved truck-train system for transporting both passengers and freight by railway.
Intermodal transport systems utilizing a combination of truck-train technology are well known to those skilled in the art. Many state and local governments have enacted legislation which taxes and regulates truck traffic to reduce road damage and traffic accidents.
To overcome these disadvantages the industry has devised many systems for combining truck-trailers with railroad equipment. Historically the first of these systems utilized railroad flatcars to carry truck-trailers in a so-called piggy-back method which eliminated to need to unload the contents of the truck-trailer.
It was soon recognized that the flatcar could be eliminated entirely and replaced by a railway dolly or so-called bogie. For example, U.S. Pat. No. 4,653,966 discloses such a system wherein a semi-trailer is driven onto a bogie. However, such a system requires a large truck turning area and a high degree of driver skill to accomplish the loading process. This system requires a separate incline ramp to load the trailer onto the dolly and if a separate incline ramp is not available at the destination, the trailer cannot be unloaded.
Another system is disclosed in U.S. Pat. No. 5,107,772 that uses a railway bogie incorporating a platform and pivot pin adapted to connect directly to a truck-trailer. The platform is raised by a pneumatic system integrated into the bogie to couple it to the underside of the trailer.
All of the prior art truck-train systems utilizing railway dollies or bogies have proven to be less than desirable by requiring additional equipment for their operation such as special lifting cranes necessary to mount the truck-trailers on the railway dollies and separate switching engines for moving the truck-trailers once they have been installed on a dolly.
Further, many of the prior art truck-train systems require the use of a railroad turntable device and a complex loading area to link the truck-trailers together for transport.
Thus, the Improved Intermodal Transport System of the present invention has been developed to overcome the deficiencies in prior art truck-train systems.
2. Description of Related Prior Art
U.S. Pat. No. 4,653,966 to Bakka et al. discloses a truck-train system wherein a semi-trailer is driven onto a bogie. Such a system requires a large truck turning area, a separate incline ramp, and a high degree of driver skill to accomplish the loading process. Further, if a separate incline rail is not available at the destination, the trailers cannot be unloaded.
U.S. Pat. No. 5,107,772 to Jacques Viens discloses a rail bogie for transporting semi-trailers comprising a truck having a wheel-mounted chassis and a fifth wheel frame above the chassis. Power jacks or inflatable balloons are mounted between this chassis and the frame for moving the latter vertically between a low and a high position relative to the chassis. The frame is raised by a pneumatic system to couple it to the underside of the trailer.
U.S. Pat. No. 4,416,571 to Robert A. Krause discloses a truck and rail transportation system wherein an elongated truck container can be carried either by rail or on a highway by a conventional truck tractor. The container includes a pair of dolly engaging pins fixed to its floor at the opposite ends thereof. The pins are adapted to engage a fifth wheel mechanism mounted on a dolly having wheels thereon adapted to engage conventional railroad rails.
U.S. Pat. No. 5,431,110 to George W. Adams discloses a truck-train system that provides for the mounting and dismounting of a truck-trailer from a railway dolly employing a moment arm reaction locking mechanism that automatically centers and engages the truck-trailer in position on the railway dolly.
U.S. Pat. No. 5,020,445 to George W. Adams discloses a truck-trail system wherein a railway dolly or bogie is utilized to support the front end of one truck-trailer and the rear end of another truck-trailer. A pair of truck-trailer support members are pivotally connected to the railway dolly. They are provided with a fixed incline ramp to raise and guide the truck-trailer onto the respective support member. The railway dolly is provided with a pair of fifth wheel mechanisms and standard railway couplers at each end.
U.S. Pat. No. 5,601,030 to Michael F. Brouillette discloses a railroad bogie with a pneumatic system and lifting mechanism for connecting truck-trailers in an articulated train. The bogie functions to lift the rear end and the front end of adjacent truck trailers respectively off the ground for transport by rail.
U.S. Pat. No. 4,773,336 to Robert M. Orb discloses a road/rail transport system comprising rail bogies of the kind having two axles and being attachable to a semi-trailer to convert the same to railroad travel.
U.S. Pat. No. 5,537,931 to Thomas G. Donkin discloses a rail bogie for connection with an intermodal or rail highway trailer having convention highway wheels. The rail bogie includes an adapter engageable with a trailer and incorporates a lift mechanism for enabling the adapter to be lowered or collapsed for insertion beneath a trailer for raising the trailer wheels off the ground.
U.S. Pat. No. 5,017,064 to George B. Kirwan et al. discloses an intermodal transport system designed for use in hauling semi-trailers by means of railway bogies. The system combines a turntable and spring-loaded chock design to enable the efficient loading and unloading of semi-trailers.
U.S. Pat. No. 5,016,544 to Ronald F. Woollam discloses a convertible road/rail power vehicle including a tractor unit provided with retractable wheel sets and rail equipment that enable it to operated on either highways or railway tracks and when on rail to pull a plurality of railway cars.
Finally, U.S. Pat. No. 5,619,931 to Harry Madison discloses a road and rail vehicle having a truck tractor vehicle frame such that it is street legal, but also provides sufficient power to move freight cars on low density rail lines or at other desired locations. The vehicle has a transfer case to provide front wheel drive by road wheels when the vehicle is in a highway mode and to provide rear wheel drive by rail wheels when in a rail mode.